The structure and function of phytochrome A: the roles of the entire molecule and of its various parts

Abstract

Phytochrome A is readily cleavable by proteolytic agents to yield an amino-terminal fragment of 66 kilodalton (kDa), which consists of residues 1 to approximately 600, and a dimer of the carboxy-terminal 55-kDa fragment, from residue 600 or so to the carboxyl terminus. The former domain, carrying the tetrapyrrole chromophore, has been studied extensively because of its photoactivity, while less attention has been paid to the non-chromophoric portion until quite recently. However, the evidence gathered to date suggests that this domain is also of great improtance. We present here a review of the structure and the biochemical and physiological functions of the two domains, of parts of these domains, and of the cooperation between them.

Phylogenetic and biogeographic complexity of Magnoliaceae in the Northern Hemisphere inferred from three nuclear data sets

“…Since nuclear markers have been generally shown to provide stronger phylogenetic signals than many plastid sequences (Wolfe et al, 1987;Small et al, 2004), we herein use three nuclear genes to resolve the phylogenetic relationships of Magnoliaceae. Phytochrome 6 evolution in land plants has been shown to result from a series of gene duplications (e.g., PHYA, PHYB, PHYC, and PHYE) that have led to independent and functionally distinct lines (Mathews et al, 1995;Mathews and Sharrock 1996;Manabe and Nakazawa, 1997;Mathews et al 2003). Nucleotide variation at phytochrome loci has been useful in various phylogenetic studies of basal angiosperms and of several other angiosperm families (Kolukisaoglu et al, 1995;Mathews and Donoghue, 1999).…”